Audition has a cool loudness match feature as well that works pretty well. It matches overall volume levels, so the perceived level can be matched, not just peak levels. If the tracks are very different, its tough to totally nail this, but for two similar samples, it works very well. You also don't have to actually have it do the adjustment, you can just see how different two examples are.
Here's a screen snap. I just threw 2 random files in.
LoudnessMatch.jpg
I can hit a button and it will adjust the levels of the 2 files to match.